Direct Reductive Quinolyl β-C-H Alkylation by Multispherical Cavity Carbon-Supported Cobalt Oxide Nanocatalysts

Until now, the selective (hetero)aryl C-H alkylation without the assistance of directing groups or preinstallation of functionalities still remains a highly challenging goal. Herein, by developing acid-resistant multispherical cavity carbon-supported cobalt oxide nanocatalysts (CoOx/MSCC) and a hydrogen transfer-mediated activation mode for non activated N-heteroaromatics, we present a direct reductive quinolyl and isoquinolyl beta-C-H alkylation with various aldehydes as the alkylating agents. The catalytic transformation features broad substrate scope, good functional tolerance, use of Earth-abundant and reusable cobalt catalysts, and no need for prefunctionalizations, demonstrating that the developed nanocatalysts enable one to directly functionalize inert N-heteroaryl systems that are difficult to realize by organometallic complexes.